Multidisciplinary tumor boards should be the rule when dealing with cancer patients, where decisions on diagnosis and treatment approaches are taken together with all the specialists involved (oncologists, radiologists, surgeons, pathologists, etc.). Regarding biopsies and tumor specimen, collaboration between surgeons, interventional radiologists, and pathologists is crucial to obtain an appropriate diagnosis and delineate future management plan. Also, understanding of the disease, of its biology and natural evolution, the implication of margins, for instance, or the heterogeneity within the tumor is crucial for all the specialists to avoid mistakes and/or morbidity for these patients. In this chapter, general principles on pediatric tumor pathology and surgical details will be discussed, along with specific particularities of the most common pediatric solid tumors and their management.